A ball is thrown upwards from the ground with a velocity of 30m/s. How long will it take to reach a point 10.0m above the ground on its way down?
Vf = Vo + gt = 0.
30 - 9.8t = 0,
-9.8t = -30,
t = 3.06s,up.
d = Vo*t + 0.5gt^2.
d = 30*3.06 - 0.5*9.8*(3.06^2,
d = 91.8 - 45.88 = 45.92m,up.
d=0 + 0.5*9.8*t^2=45.9 -10=35.9m,down.
4.9t^2 = 35.9,
t^2 = 7.33,
t = 2.7s,down.
t(tot.) = 3.06 + 2.7 = 5.76s.